Restoring a metabolic pathway.
Gluconeogenesis is blocked in a strain of Escherichia coli that is deficient in triosephosphate isomerase, but it was restored by the insertion of a plasmid coding for an L-glyceraldehyde 3-phosphate reductase (YghZ). This reductase provides a "bypass" that produces dihydroxyacetone phosphate (DHAP) by the consecutive enzyme-catalyzed reduction of L-glyceraldehyde 3-phosphate ( L-GAP) by NADPH to give L-glycerol 3-phosphate and reoxidation by NAD(+) catalyzed by endogenous L-glycerol 3-phosphate dehydrogenase to give DHAP. The origin of cellular L-GAP remains to be determined.
Richard
John P
JP
Department of Chemistry, University at Buffalo, SUNY, Buffalo, New York 14260-3000, USA. jrichard@chem.buffalo.edu
D004099:Dihydroxyacetone Phosphate / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D005943:Gluconeogenesis / Q000235:genetics; D005986:Glyceraldehyde 3-Phosphate / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D010957:Plasmids; D013401:Sugar Alcohol Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D014305:Triose-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism*
D005986:Glyceraldehyde 3-Phosphate; D004099:Dihydroxyacetone Phosphate; D013401:Sugar Alcohol Dehydrogenases; C028041:glyceraldehyde reductase; D014305:Triose-Phosphate Isomerase